In the waste ground by the edge of Hollingside wood tall spikes of rosebay willowherb, tipped with the last of their purple flowers, were releasing their downy seeds. Each seed pod split into four segments that peeled back like brittle banana skins, allowing every passing breeze to tug free the cotton-plumed seeds and sweep them aloft into the rising thermals of a sultry afternoon. A forest bug, its angular armour trailing white down as it blundered among the seed pods, paused to groom willowherb cotton from its antennae. Some seeds travelled no farther than the spiders' webs, rendering every stealthily-spun thread of gossamer visible with their snared white tufts.

A passing comma butterfly floated into view and settled on a yellow ragwort inflorescence, shuffled around until its outspread wings were angled perfectly to absorb the sun's rays and then uncoiled its tongue to feed. I knelt to take its photograph, careful not to disturb it with my shadow, but just as I began to press the shutter release it rose, fluttered around my head then glided a few metres away, settling on a patch of spear thistle. It repeated this performance three times more, dancing from flower to flower, waiting until the last moment before fleeing, leaving me with four pictures of flowers but no butterfly.

Then my quarry settled on a down-covered stem, deep inside the willow-herb thicket. I eased between the stems, liberating a blizzard of cottony seeds that clung to my clothes. I held the camera at arm's length, pointed in the general direction of the basking butterfly, and pressed the release. Then, with my senses as tickled as those of the forest bug, I had to turn away to groom willowherb cotton from my face. When I looked again I had my picture – but the comma had vanished.